RESUMO
Water pollution, significantly influenced by the discharge of synthetic dyes from industries, such as textiles, poses a persistent global threat to human health. Among these dyes, methylene blue, particularly prevalent in the textile sector, exacerbates this issue. This study introduces an innovative approach to mitigate water pollution through the synthesis of nanomaterials using biomass-derived carbon quantum dots (CQDs) from grape pomace and watermelon peel. Utilizing the hydrothermal method at temperatures between 80 and 160 °C over periods ranging from 1 to 24 h, CQDs were successfully synthesized. A comprehensive characterization of the CQDs was performed using UV-visible spectroscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, Raman spectroscopy, and luminescence spectroscopy, confirming their high quality. The photocatalytic activity of the CQDs in degrading methylene blue was evaluated under both sunlight and incandescent light irradiation, with measurements taken at 20 min intervals over a 2 h period. The CQDs, with sizes ranging from 1-10 nm, demonstrated notable optical properties, including upconversion and down-conversion luminescence. The results revealed effective photocatalytic degradation of methylene blue under sunlight, highlighting the potential for scalable production of these cost-effective catalytic nanomaterials for synthetic dye degradation.
RESUMO
Plant viruses such as brome mosaic virus and cowpea chlorotic mottle virus are effectively purified through PEG precipitation and sucrose cushion ultracentrifugation. Increasing ionic strength and an alkaline pH cause the viruses to swell and disassemble into coat protein subunits. The coat proteins can be reassembled into stable virus-like particles (VLPs) that carry anionic molecules at low ionic strength and through two-step dialysis from neutral pH to acidic buffer. VLPs have been extensively studied due to their ability to protect and deliver cargo, particularly RNA, while avoiding degradation under physiological conditions. Furthermore, chemical functionalization of the surface of VLPs allows for the targeted drug delivery. VLPs derived from plants have demonstrated great potential in nanomedicine by offering a versatile platform for drug delivery, imaging, and therapeutic applications.
Assuntos
Vírus de Plantas , Vírus de Plantas/genética , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Vírion/química , Vírion/genética , Bromovirus/química , Bromovirus/genética , RNA/química , Concentração de Íons de Hidrogênio , RNA Viral/genéticaRESUMO
We present a combination of light-sheet excitation and two-dimensional fluorescence intensity ratio (FIR) measurements as a simple and promising technique for three-dimensional temperature mapping. The feasibility of this approach is demonstrated with samples fabricated with sodium yttrium fluoride nanoparticles co-doped with rare-earth ytterbium and erbium ions (NaYF4:Yb3+/Er3+) incorporated into polydimethylsiloxane (PDMS) as a host material. In addition, we also evaluate the technique using lipid-coated NaYF4:Yb3+/Er3+ nanoparticles immersed in agar. The composite materials show upconverted (UC) fluorescence bands when excited by a 980 nm near-infrared laser light-sheet. Using a single CMOS camera and a pair of interferometric optical filters to specifically image the two thermally-coupled bands (at 525 and 550 nm), the two-dimensional FIR and, hence, the temperature map can be readily obtained. The proposed method can take optically sectioned (confocal-like) images with good optical resolution over relatively large samples (up to the millimetric scale) for further 3D temperature reconstruction.
RESUMO
Composites of Ag and TiO2 nanoparticles were synthesized in situ on cotton fabrics using sonochemical and solvothermal methods achieving the successive formation of Ag-NPs and Ti-NPs directly on the fabric. The impregnated fabrics were characterized using ATR-FTIR spectroscopy; high-resolution microscopy (HREM); scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS); Raman, photoluminescence, UV-Vis, and DRS spectroscopies; and by tensile tension tests. Results showed the successful formation and impregnation of NPs on the cotton fabric, with negligible leaching of NPs after several washing cycles. The photocatalytic activity of supported NPs was assessed by the degradation of methyl blue dye (MB) under solar and UV irradiation revealing improved photocatalytic activity of the Ag-TiO2/cotton composites due to a synergy of both Ag and TiO2 nanoparticles. This behavior is attributed to a diminished electron-hole recombination effect in the Ag-TiO2/cotton samples. The biocide activity of these composites on the growth inhibition of Staphylococcus aureus (Gram+) and Escherichia coli (Gram-) was confirmed, revealing interesting possibilities for the utilization of the functionalized cotton fabric as protective cloth for medical applications.
RESUMO
Gaucher disease is a genetic disorder and the most common lysosomal disease caused by the deficiency of enzyme ß-glucocerebrosidase (GCase). Although enzyme replacement therapy (ERT) is successfully applied using mannose-exposed conjugated glucocerebrosidase, the lower stability of the enzyme in blood demands periodic intravenous administration that adds to the high cost of treatment. In this work, the enzyme ß-glucocerebrosidase was encapsulated inside virus-like nanoparticles (VLPs) from brome mosaic virus (BMV), and their surface was functionalized with mannose groups for targeting to macrophages. The VLP nanoreactors showed significant GCase catalytic activity. Moreover, the Michaelis-Menten constants for the free GCase enzyme (KM =0.29â mM) and the functionalized nanoreactors (KM =0.32â mM) were similar even after chemical modification. Importantly, the stability of enzymes under physiological conditions (pHâ 7.4, 37 °C) was enhanced by ≈11-fold after encapsulation; this is beneficial for obtaining a higher blood circulation half-life, which may decrease the cost of therapy by reducing the requirement of multiple intravenous injections. Finally, the mannose receptor targeted enzymatic nanoreactors showed enhanced internalization into macrophage cells. Thus, the catalytic activity and cell targeting suggest the potential of these nanoreactors in ERT of Gaucher's disease.
Assuntos
Doença de Gaucher , Terapia de Reposição de Enzimas , Doença de Gaucher/tratamento farmacológico , Doença de Gaucher/genética , Glucosilceramidase/genética , Humanos , Manose , NanotecnologiaRESUMO
Enzymatic nanoreactors were obtained by galactose-1-phosphate uridylyl-transferase (GALT) encapsulation into plant virus capsids by a molecular self-assembly strategy. The aim of this work was to produce virus-like nanoparticles containing GALT for an enzyme-replacement therapy for classic galactosemia. The encapsulation efficiency and the catalytic constants of bio-nanoreactors were determined by using different GALT and virus coat protein ratios. The substrate affinity of nanoreactors was slightly lower than that of the free enzyme; the activity rate was 16 % of the GALT free enzyme. The enzymatic nanoreactors without functionalization were internalized into different cell lines including fibroblast and kidney cells, but especially into hepatocytes. The enzymatic nanoreactors are an innovative enzyme preparation with potential use for the treatment of classic galactosemia.
Assuntos
Bromovirus/metabolismo , Proteínas do Capsídeo/química , Composição de Medicamentos/métodos , UTP-Hexose-1-Fosfato Uridililtransferase/química , Animais , Proteínas do Capsídeo/isolamento & purificação , Linhagem Celular , Endocitose , Fluoresceína-5-Isotiocianato/química , Galactosemias/tratamento farmacológico , Galactosemias/patologia , Humanos , Cinética , Camundongos , Nanotecnologia , UTP-Hexose-1-Fosfato Uridililtransferase/metabolismo , UTP-Hexose-1-Fosfato Uridililtransferase/uso terapêuticoRESUMO
Most of the drugs used in chemotherapy should be activated by a transformation catalyzed by cytochrome P450 (CYP) enzymes. In this work, bacteriophage P22 virus-like particles (VLPs) containing CYP activity, immunologically inert and functionalized in order to be recognized by human cervix carcinoma cells and human breast adenocarcinoma cells were designed. The CYP was encapsulated inside the virus capsid obtained from the bacteriophage P22. CYP and coat protein were both heterologously expressed in E. coli. The VLPs with enzymatic activity were covered with polyethylene glycol that was functionalized in its distal end with folic acid in order to be recognized by folate receptors exhibited on tumor cells. The capacity of biocatalytic VLPs to be recognized and internalized into tumor cells is demonstrated. The VLP-treated cells showed enhanced capacity for the transformation of the pro-drug tamoxifen, which resulted in an increase of the cell sensitivity to this oncological drug. In this work, the potential use of biocatalytic VLPs vehicles as a delivery system of medical relevant enzymes is clearly demonstrated. In addition to cancer treatment, this technology also offers an interesting platform as nano-bioreactors for intracellular delivery of enzymatic activity for other diseases originated by the lack of enzymatic activity.
Assuntos
Bacteriófago P22/enzimologia , Capsídeo/enzimologia , Sistema Enzimático do Citocromo P-450/metabolismo , Nanopartículas/química , Tamoxifeno/administração & dosagem , Bacteriófago P22/química , Bacteriófago P22/genética , Biocatálise , Capsídeo/química , Linhagem Celular Tumoral , Sistema Enzimático do Citocromo P-450/química , Sistemas de Liberação de Medicamentos , Ativação Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Polietilenoglicóis/químicaRESUMO
BACKGROUND: The intracellular delivery of enzymes for therapeutic use has a promising future for the treatment of several diseases such as genetic disorders and cancer. Virus-like particles offer an interesting platform for enzymatic delivery to targeted cells because of their great cargo capacity and the enhancement of the biocatalyst stability towards several factors important in the practical application of these nanoparticles. RESULTS: We have designed a nano-bioreactor based on the encapsulation of a cytochrome P450 (CYP) inside the capsid derived from the bacteriophage P22. An enhanced peroxigenase, CYPBM3, was selected as a model enzyme because of its potential in enzyme prodrug therapy. A total of 109 enzymes per capsid were encapsulated with a 70 % retention of activity for cytochromes with the correct incorporation of the heme cofactor. Upon encapsulation, the stability of the enzyme towards protease degradation and acidic pH was increased. Cytochrome P450 activity was delivered into Human cervix carcinoma cells via transfecting P22-CYP nanoparticles with lipofectamine. CONCLUSION: This work provides a clear demonstration of the potential of biocatalytic virus-like particles as medical relevant enzymatic delivery vehicles for clinical applications.
Assuntos
Bacteriófago P22/química , Capsídeo/química , Sistema Enzimático do Citocromo P-450/administração & dosagem , Portadores de Fármacos/química , Proteínas do Capsídeo/química , Linhagem Celular Tumoral , Sistema Enzimático do Citocromo P-450/uso terapêutico , Terapia Enzimática , Feminino , Células HeLa , Humanos , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/enzimologiaRESUMO
This work shows, for the first time, the encapsulation of a highly relevant protein in the biomedical field into virus-like particles (VLPs). A bacterial CYP variant was effectively encapsulated in VLPs constituted of coat protein from cowpea chlorotic mottle virus (CCMV). The catalytic VLPs are able to transform the chemotherapeutic pro-drug, tamoxifen, and the emerging pro-drug resveratrol. The chemical nature of the products was identified, confirming similar active products than those obtained with human CYP. The enzymatic VLPs remain stable after the catalytic reaction. The potential use of these biocatalytic nanoparticles as targeted CYP carriers for the activation of chemotherapy drugs is discussed.